archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-15 08:34:30 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

8059066: CardTableModRefBS might commit the same page twice

Browse source 
Reviewed-by: tschatzl, kbarrett, jmasa
This commit is contained in:
Erik Helin 2014-12-02 09:53:30 +01:00
parent 902d2139f6
commit cbe8efabfe
2 changed files with 69 additions and 23 deletions
Download patch file Download diff file Expand all files Collapse all files

43
hotspot/src/share/vm/memory/cardTableModRefBS.cpp
View file

@ -275,29 +275,26 @@ void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
// the new_end_aligned does not intrude onto the committed
// space of another region.
int ri = 0;
for (ri = 0; ri < _cur_covered_regions; ri++) {
if (ri != ind) {
if (_committed[ri].contains(new_end_aligned)) {
// The prior check included in the assert
// (new_end_aligned >= _committed[ri].start())
// is redundant with the "contains" test.
// Any region containing the new end
// should start at or beyond the region found (ind)
// for the new end (committed regions are not expected to
// be proper subsets of other committed regions).
assert(_committed[ri].start() >= _committed[ind].start(),
"New end of committed region is inconsistent");
new_end_aligned = _committed[ri].start();
// new_end_aligned can be equal to the start of its
// committed region (i.e., of "ind") if a second
// region following "ind" also start at the same location
// as "ind".
assert(new_end_aligned >= _committed[ind].start(),
"New end of committed region is before start");
debug_only(collided = true;)
// Should only collide with 1 region
break;
}
for (ri = ind + 1; ri < _cur_covered_regions; ri++) {
if (new_end_aligned > _committed[ri].start()) {
assert(new_end_aligned <= _committed[ri].end(),
"An earlier committed region can't cover a later committed region");
// Any region containing the new end
// should start at or beyond the region found (ind)
// for the new end (committed regions are not expected to
// be proper subsets of other committed regions).
assert(_committed[ri].start() >= _committed[ind].start(),
"New end of committed region is inconsistent");
new_end_aligned = _committed[ri].start();
// new_end_aligned can be equal to the start of its
// committed region (i.e., of "ind") if a second
// region following "ind" also start at the same location
// as "ind".
assert(new_end_aligned >= _committed[ind].start(),
"New end of committed region is before start");
debug_only(collided = true;)
// Should only collide with 1 region
break;
}
}
#ifdef ASSERT

49
hotspot/test/gc/TestCardTablePageCommits.java Normal file
View file

@ -0,0 +1,49 @@
/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import com.oracle.java.testlibrary.JDKToolFinder;
import com.oracle.java.testlibrary.OutputAnalyzer;
import com.oracle.java.testlibrary.ProcessTools;
import com.oracle.java.testlibrary.Platform;
/*
* @test TestCardTablePageCommits
* @key gc
* @bug 8059066
* @summary Tests that the card table does not commit the same page twice
* @library /testlibrary
* @run driver TestCardTablePageCommits
*/
public class TestCardTablePageCommits {
public static void main(String args[]) throws Exception {
// The test is run with a small heap to make sure all pages in the card
// table gets committed. Need 8 MB heap to trigger the bug on SPARC
// because of 8kB pages, assume 4 KB pages for all other CPUs.
String Xmx = Platform.isSparc() ? "-Xmx8m" : "-Xmx4m";
String[] opts = {Xmx, "-XX:NativeMemoryTracking=detail", "-XX:+UseParallelGC", "-version"};
ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(opts);
OutputAnalyzer output = new OutputAnalyzer(pb.start());
output.shouldHaveExitValue(0);
}
}